1. Field of the Invention
The present invention relates to a jet-propulsion personal watercraft (PWC) which ejects water pressurized and accelerated by a water jet pump rearward and planes on a water surface as the resulting reaction. More particularly, the present invention relates to an air-intake structure of an engine for driving the water jet pump mounted in a body of the personal watercraft.
2. Description of the Related Art
In recent years, so-called jet-propulsion personal watercraft have been widely used in leisure, sport, rescue activities, and the like. The personal watercraft is configured to have a water jet pump that pressurizes and accelerates water sucked from a water intake generally provided on a hull bottom surface and ejects it rearward from an outlet port. Thereby, the personal watercraft is propelled.
In the personal watercraft, the engine is contained in a FRP (Fiber Reinforced Plastic) body constituted by a deck and a hull. Many of the personal watercraft are straddle-type personal watercraft and stand-up type personal watercraft. In these personal watercraft, an engine room in the body that contains the engine has a limited space. Among these personal watercraft, in the straddle-type personal watercraft having the engine room below the seat, the size of the engine room is inevitably limited by the size of the seat straddled by a rider. Under the circumstances, in the personal watercraft, it is necessary to efficiently place the engine in such a limited space in the deck, together with associated components in the air-intake system, an exhaust system, and the like.
Noises generated in an air-intake pipe of the engine, i.e., noises resulting from oscillation of the intake air in the air-intake pipe, are uncomfortable to the rider. Also, it is essential that water ingress from an air-intake passage into an inside of the engine be avoided.